/* Global reset and custom variables based on professional corporate palettes (deep navy and technical blue) */
:root {
    --primary-color: #1a365d; /* Deep corporate Navy */
    --accent-color: #3182ce;  /* Engineering blue */
    --dark-color: #2d3748;    /* Charcoal text */
    --light-color: #f7fafc;   /* Soft off-white */
    --border-color: #e2e8f0;
    --white: #ffffff;
    --font-main: 'Inter', 'Noto Sans TC', sans-serif;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    color: var(--dark-color);
    line-height: 1.6;
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

/* Typography */
h1, h2, h3, h4 {
    font-weight: 700;
    color: var(--primary-color);
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

ul {
    list-style: none;
}

/* Button styles */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 5px;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
    text-align: center;
}

.btn-primary {
    background-color: var(--accent-color);
    color: var(--white);
    border: 2px solid var(--accent-color);
}

.btn-primary:hover {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-secondary {
    background-color: transparent;
    color: var(--white);
    border: 2px solid var(--white);
    margin-left: 15px;
}

.btn-secondary:hover {
    background-color: var(--white);
    color: var(--primary-color);
}

/* Top Bar Styling */
.top-bar {
    background-color: #111827;
    color: #e5e7eb;
    padding: 10px 0;
    font-size: 0.85rem;
}

.top-bar-flex {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.top-info span {
    margin-right: 20px;
}

.top-info i {
    color: var(--accent-color);
    margin-right: 6px;
}

.lang-switch-btn {
    background-color: #374151;
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 0.8rem;
}

.lang-switch-btn:hover {
    background-color: var(--accent-color);
}

/* Navbar Styling */
.navbar {
    background-color: var(--white);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 15px 0;
}

.nav-flex {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.logo-brand {
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--primary-color);
    line-height: 1;
    letter-spacing: 2px;
}

.logo-sub {
    font-size: 0.75rem;
    font-weight: 500;
    color: #718096;
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    gap: 25px;
}

.nav-links a {
    font-weight: 500;
    font-size: 0.95rem;
    color: #4a5568;
    position: relative;
    padding: 5px 0;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--accent-color);
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: var(--accent-color);
    transition: width 0.3s ease;
}

.nav-links a:hover::after {
    width: 100%;
}

.mobile-menu-toggle {
    display: none;
    font-size: 1.5rem;
    background: none;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
}

/* Hero Section */
.hero-section {
    background: linear-gradient(135deg, rgba(26,54,93,0.95) 0%, rgba(45,55,72,0.85) 100%), url('https://images.unsplash.com/photo-1581092160607-ee22621dd758?q=80&w=1920') no-repeat center center/cover;
    height: 70vh;
    min-height: 450px;
    display: flex;
    align-items: center;
    color: var(--white);
    text-align: center;
}

.hero-content {
    max-width: 800px;
}

.hero-content h1 {
    font-size: 3rem;
    color: var(--white);
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.2rem;
    color: #cbd5e0;
    line-height: 1.6;
}

/* Sections General */
section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-header h2 {
    font-size: 2.2rem;
    position: relative;
    padding-bottom: 15px;
    margin-bottom: 10px;
}

.section-header h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background-color: var(--accent-color);
}

.section-subtitle {
    color: #718096;
    font-size: 1.1rem;
}

/* About Section */
.about-section {
    background-color: var(--white);
}

.about-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 40px;
    align-items: center;
}

.about-text p {
    font-size: 1.05rem;
    color: #4a5568;
    line-height: 1.8;
}

.about-stats-card {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 30px;
    border-radius: 8px;
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.stat-item {
    border-left: 4px solid var(--accent-color);
    padding-left: 15px;
}

.stat-num {
    display: block;
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--white);
    line-height: 1;
    margin-bottom: 5px;
}

.stat-lbl {
    font-size: 0.9rem;
    color: #cbd5e0;
}

/* Services Section */
.services-section {
    background-color: var(--light-color);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 25px;
}

.service-card {
    background-color: var(--white);
    padding: 30px 20px;
    border-radius: 8px;
    border-top: 4px solid var(--primary-color);
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05);
    transition: transform 0.3s ease, border-color 0.3s ease;
}

.service-card:hover {
    transform: translateY(-5px);
    border-top-color: var(--accent-color);
}

.service-icon {
    font-size: 2.5rem;
    color: var(--accent-color);
    margin-bottom: 20px;
}

.service-card h3 {
    font-size: 1.2rem;
    margin-bottom: 15px;
}

.service-card p {
    color: #718096;
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Projects Section */
.projects-section {
    background-color: var(--white);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.project-card {
    background-color: var(--light-color);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05);
    border-left: 5px solid var(--primary-color);
    transition: all 0.3s ease;
}

.project-card:hover {
    transform: scale(1.02);
    border-left-color: var(--accent-color);
}

.project-content {
    padding: 25px;
}

.project-tag {
    display: inline-block;
    background-color: #ebf8ff;
    color: #2b6cb0;
    font-size: 0.75rem;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: 50px;
    margin-bottom: 15px;
    text-transform: uppercase;
}

.project-card h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
}

.project-details li {
    font-size: 0.95rem;
    color: #4a5568;
    margin-bottom: 8px;
}

.project-details i {
    color: #48bb78;
    margin-right: 8px;
}

/* Clients Section */
.clients-section {
    background-color: var(--light-color);
    text-align: center;
}

.clients-list {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 30px;
}

.client-logo-box {
    background-color: var(--white);
    padding: 15px 30px;
    border-radius: 5px;
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--primary-color);
    border: 1px solid var(--border-color);
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 150px;
}

/* Contact Section */
.contact-section {
    background-color: var(--white);
}

.contact-container {
    max-width: 800px;
    margin: 0 auto;
}

.contact-info-list {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.contact-card-item {
    background-color: var(--light-color);
    padding: 25px;
    border-radius: 8px;
    display: flex;
    align-items: flex-start;
    gap: 20px;
    border: 1px solid var(--border-color);
}

.contact-card-item i {
    font-size: 1.8rem;
    color: var(--accent-color);
    background-color: #ebf8ff;
    padding: 15px;
    border-radius: 50%;
}

.contact-card-item h3 {
    font-size: 1.1rem;
    margin-bottom: 5px;
}

.contact-card-item p {
    color: #4a5568;
    font-size: 0.95rem;
}

/* Footer Section */
.footer {
    background-color: #1a202c;
    color: var(--white);
    padding: 60px 0 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr 1fr 1.5fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col h3 {
    color: var(--white);
    font-size: 1.6rem;
    margin-bottom: 15px;
    letter-spacing: 1px;
}

.footer-col h4 {
    color: var(--white);
    font-size: 1.1rem;
    margin-bottom: 20px;
}

.footer-links li {
    margin-bottom: 10px;
}

.footer-links a {
    color: #a0aec0;
    font-size: 0.95rem;
}

.footer-links a:hover {
    color: var(--accent-color);
    padding-left: 5px;
}

.footer-contact p {
    color: #a0aec0;
    font-size: 0.95rem;
    margin-bottom: 12px;
    line-height: 1.5;
}

.footer-bottom {
    background-color: #111827;
    padding: 20px 0;
    text-align: center;
    font-size: 0.85rem;
    color: #718096;
    border-top: 1px solid #2d3748;
}

/* Responsive Styles */
@media (max-width: 991px) {
    .about-grid {
        grid-template-columns: 1fr;
    }
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: block;
    }
    
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--white);
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        border-top: 1px solid var(--border-color);
        gap: 15px;
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .top-bar-flex {
        flex-direction: column;
        gap: 10px;
        text-align: center;
    }
    
    .hero-content h1 {
        font-size: 2.2rem;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
}